When Alan O'Connor first came north to Ulster, a trip to La Rochelle and tomorrow's visit to the Stade Marcel Deflandre would have brought inevitable talk surrounding the province's long losing run in France.

When Alan O'Connor first came north to Ulster, a trip to La Rochelle and tomorrow's visit to the Stade Marcel Deflandre would have brought inevitable talk surrounding the province's long losing run in France.

Since the former Skerries lock was brought to Kingspan Stadium in 2012, though, he has been witness to some memorable days on the other side of the Channel.

He had watching briefs for that significant first win against Castres, the triumph over Montpellier the next season and the hair-raising comeback in Oyonnax, while one of his most memorable days in the Ulster jersey came almost two years ago when the old artisans of European rugby Toulouse were seen off at the Stade Ernest-Wallon.

It was his first experience of Top 14 opposition, though, that saw him pitted against what was, prior to tomorrow, his most sizeable challenge.

Up against Toulon in 2015, who were then still the undisputed best team in Europe, O'Connor was making his European debut in a weakened side that put in a more spirited showing in the Cote d'Azur than the 60-22 final scoreline would suggest.

Up against Romain Taofifénua, the 6ft 7in French lock who comfortably tips the scales at over 20 stone, it was an eye-opening experience for O'Connor going head-to-head with the largest player he had ever seen in the flesh.

As the 25-year-old wryly notes, though, his opposite number tomorrow, Fijian Jone Qovu, who made his name as a cult hero at Racing 92, steals away that crown.

"It would have been one of the Toulon boys, Romain Taofifénua," he replied when asked for the biggest opposition he had come up against in his career.

"Qovu takes the biscuit on that one, though... or two or three biscuits I think."

Built like a prop but undersized when compared to his tighthead Uini Atonio, Qovu's appearance can be deceptive, and he was still buzzing around well into the second half against Harlequins last week.

Against this imposing physical unit, O'Connor knows Ulster's pack must nail their basics.

"We know what we are like and what we can do whenever we have the ball," he said.

"We just have to go there and boss the ball and make sure we get over the gain line, then it should be a good day for us.

"We have to make sure we have two boys tackling them at the same time because you can't allow any of those boys to get a head of steam up.

"You have to stop them with force. They are very clinical, their backs are incredibly quick and their centres are very strong up the middle as well.

"They are very good around the park so we have to make sure we tag those offload channels and make sure we get good and low and tag the ball.

"If they get behind you, they are pretty unstoppable when you have some boys around 140kg running over you."

A red letter day for locals, tomorrow's hosts can seemingly not wait for their first home game in this competition but, even without the sense of occasion, the 16,000-capacity stadium is usually rocking.

With another sell-out expected, and their opponents boasting a home record that has seen them beaten just once on their own patch since the start of last season, O'Connor is expecting a red-hot welcome.

"Jono (Gibbes) was there a lot when he was over there so he knows what it's like and has told us what to expect, ballboys maybe not giving us the ball quickly as we want for lineouts and stuff," he added. "But we'll work around that and I'm looking forward to the French atmosphere."